The present invention relates to a side airbag apparatus that protects an occupant seated in a vehicle seat from an impact by deploying and inflating an airbag main body on a side of the occupant when the impact is applied to a vehicle from a side.
A side airbag apparatus having an airbag and an inflator is effective as an apparatus that protects an occupant seated in an automobile seat when an impact is applied to an automobile from a side, for example, due to a side collision. One form of the side airbag apparatus has been disclosed in, for example, Japanese Laid-Open Patent Publication No. 2013-035535. More specifically, an airbag includes an airbag main body that forms an outer shell and a vertical partition having a gas flow restrictor such as a pressure regulator valve. The vertical partition divides the inside of the airbag main body into an upstream inflation portion and a downstream inflation portion. The upstream inflation portion is located rearward of the vertical partition and receives inflating gas from the inflator. The downstream inflation portion is located forward of the vertical partition and receives the inflating gas that has passed through the upstream inflation portion and the gas flow restrictor.
If a lateral impact is applied to a body side portion, such as a side door, of a vehicle that employs the side airbag apparatus, the inflator supplies inflating gas to the upstream inflation portion to deploy and inflate the upstream inflation portion between an occupant and the body side portion that bulges inward of the vehicle. The inflating gas in the upstream inflation portion flows into the downstream inflation portion through the gas flow restrictor and deploys and inflates the downstream inflation portion. The upstream inflation portion and the downstream inflation portion that are deployed and inflated between the occupant and the body side portion as described above restrain the occupant and reduce a lateral impact transmitted to the occupant via the body side portion.
The downstream inflation portion starts to be deployed and inflated later than the upstream inflation portion. Thus, even if any obstacle is front of the deploying airbag main body, the airbag main body is inhibited from pushing the obstacle hard unlike a case in which the airbag main body has no partition and is deployed and inflated at once.
To restrain and protect the occupant, it is effective to increase the dimension in the vehicle widthwise direction (inflation thickness) when the airbag main body is inflated, or to deploy and inflate the airbag main body in the fore-and-aft direction by a large amount. However, if the airbag main body is deployed and inflated forward by a large amount, the downstream inflation portion that is deployed and inflated in addition to the upstream inflation portion may possibly push the obstacle hard.
The conventional side airbag apparatus of the above Patent Document merely divides the airbag main body and restricts the inflation thickness of the airbag main body with the vertical partition. Thus, the side airbag apparatus is susceptible to improvement through modification of the vertical partition in restraining and protecting an occupant and inhibiting pressure on an obstacle.